Automatic rheostat-controller



(No Model.) 2 Sheets-Sheet 1.

R. WILSON. AUTOMATIC RHEOSTAT CONTROLLER.

No. 588,306. Patented Aug. 17,1897,

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(No Model.) 2 SheetsSheet 2, R. WILSON. AUTOMATIC RHEOSTAT CONTROLLER.

No. 588,306. Patented Aug. 17,1897.

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ROBERT WVILSON, OF LOUISVILLE, KENTUCKY, ASSIGNOR TO THE SULZER- VOGTMACHINE COMPANY, OF KENTUCKY.

AUTOMATIC RH EOSTAT-CONTROLLER.

SPECIFICATION forming part of Letters Patent No. 588,306, dated August17', 1897.

Serial No. 638,798. (No model.)

To all whmn it may concern.-

Be it known that 1, ROBERT WILsoN, a citizen of the United States,residing at Louisville, in the county of J eiferson and State ofKentucky, have invented certain new and useful Improvements in AutomaticRheostat- Controllers, of which the following is a full, clear, andexact description.

This invention relates to automatic rheostat-controllers for electricmotors, and is designed especially for operating electric elevators andhoists, but is not necessarily confined to such apparatus.

The object of the invention is to provide an efficientapparatus by whichthe main circuit of the motor may be closed and immediately thereafterthe controlling resistance gradually removed from the circuit by asimple push or pull upon the operating lever or cable.

The invention consists in general of the combination of a main-switcharm, a rheostat-lever, an actuating-lever, and a cam, theactuating-lever being arranged to move both the switch-lever and thecam, allowance being made for independent movements of theactuating-lever with respect to the switcharm and cam, whereby therheostat-lever and switch-arm are caused to act in succession. 7

The invention will be described in detail with reference to theaccompanying drawings, in which Figure 1 is a front elevation of theentire apparatus. Figs. 2, 3, and at are front views of the particularportions constituting my invention shown in three different positions ofoperation. Fig. 5 is a detail View of the cam, and Fig. 6 illustrates amodification of the invention.

Referring to the drawings by letter, Arepresents a boX or casing inwhich the mechanism is located and which contains a set ofresistance-coils (not shown) whose terminals respectively connect withthe contacts in segment a. This resistance is in the main circuitcontrolled by the mechanism.

Bis a main operating-lever passing into the box through an opening inits side and connecting with a short rod 1) and also with a crank btherein. Upon a stud c is pivoted a bell-crank-actuating lever, one arm0 of which has a cross-head provided at its extremities with lugs 0while the other arm 0 connects with a spring 0, surrounding a rod o andarranged to exert its pressure against the end of the arm 0 from anabutment and pivot 0 On the stud 0 there is also loosely hung aswitch'ar m d and a cam e. The switch-arm d carries the contact-clips 1and 2 and stands between the lugs c on the arm 0, so as to be struck andmoved by said lugs when the arm moves. The cam has a concentric track cand a radial track e It carries an offset e from which two lugs 6project and embrace the arm 0 The lugs 0 permit arm a to move a certaindistance before they make contact with the switch-lever. Likewise thelugs on the cam permit the arm 0 to move a certain distance before theyare struck thereby.

f is the rheostat-lever, pivoted at f and having two branch arms f and frespectively. The lever carries at its free end a contact-piece whichtravels over the segment of rheostat-contacts (1. Upon the arm f is anadjustable weight w, which tends to swing the rheostat-lever on itscenter in a direction to cut out the resistance. The arm f carries atits extremity a small roller f which bears upon the track of the cam.The motion of rheostat-lever is made gradual and regular by the dash-potg. The clips 1 and 2 are adapted to engage with the fixed contacts 3 and4 to close the main circuit, in which the rheostat is located.

The parts 5, 6, 7, 8, and 9 constitute a reversing-switch. 9 is pivotedand carries the extension 10, standing between the two lugs b on thecrank Z).

The normal position of the parts when the main switch is open is shownin Fig. 1, the resistance being all in circuit. The same position of theparts mounted on the stud c is shown in Fig. 2. When the circuit is tobe closed and the motorstarted, lever B is moved in one direction or theother and causes rod 1) to lift arm 0 and lower arm 0 These two armsmove until lug c strikes switch-lever d and lug e is struck by arm 0lever cl commences to travel along the concentric track of the cam. henthe roller f Then switchhas traveled about one-half the length of theconcentric track, spring 0 which had during this entire movement beengradually put under compression, passes its line of centers and exertsthe force stored in it to impart a quick movement to the arms a and c.This throws the clips of the switch-arm into full connection with thecontacts 3 and at and brings the roller f to the end of the concentrictrack of the cam, where the radial track begins, the position beingshown clearly in Fig. 3. Then weight 10 being released, it swings theroller inward along the radial track of the cam, causing lug e to moveaway from arm 0 while at the same time the rheostat-lever travels overthe segment of contacts, cutting out the resistance at a rate controlledby the dash-pot, the final position be ing shown in Fig. 4, where allof' the resistance is out and the motor supposed to be running fullspeed. It will thus be seen that the main switch is fully closed beforeany of the resistance is cut out and that thereafter it is graduallyremoved from the circuit.

To stop the motor, lever B is moved in the opposite direction, whichcauses arm 0 of the actuating-lever to move downward and arm 0 upward.The initial movement of arm c is accompanied by amovement of the cam,and consequently the resistance-lever is swung back to put theresistance into circuit. The entire resistance is in when roller freaches the concentric track of the cam, at which time the upper lug chas struck arm d, and simultaneously the spring passes its line ofcenters and suddenly opens the switch, all parts being left in theposition shown in Fig. 2.

The reversing-switch is only operated when the main lever B throws thecrank b and rod 6 from one side of their centers to the other, and thenit shifts just before the main switch closes. The lugs b permit thecrank to move while the main switch is opening or closing without movingthe reversing-switch lever.

Referring now to Fig. 6, which illustrates a modification of theinvention in which the cam is formed in one piece with the arm a It isprovided with the same concentric and radial tracks, but the offset cwith its lugs, which provide for the differential movement of the armand cam, is omitted. This form of the device is useful in many places,but it has the disadvantage that in closing the circuit it allows therheostat-lever to cut out some of the resistance before the main switchis closed, the reason for this being that the quick move ment caused bythe spring carries the concentric traek of the cam beyond the roller fbefore the switch is closed.

Having thus described my invention, I claim 1. I11 an automaticrheostat, the combination of an actuating-lever, a cam moved thereby, arheostat-lever controlled by the cam,and means whereby theactuating-lever is permitted to move a short distance independently ofthe cam for the purpose set forth.

2. In an automatic rheostat, the combination of a switch-lever, arheostat-lever and an actuating-lever carrying acam engaging with andcontrolling the rheostat-lever, the actuating-lever having a movementindependent of the switch-lever and the cam adapted to hold therheostat-lever stationary while the switcharm is moved and to move orpermit to move, the rheostat-lever when the switch is stationary,substantially as described.

3. In an automatic rheostat, the combination of a switch-lever, arheostat-lever, a cam controlling the latter and an actuating-lever, theactuating-lever moving the switch-lever and cam but having movementsindependent of both of them whereby the switch and rheostat are causedto be operated in succession.

4. In an automatic rheostat the combination of a reversing-switch lever,amain-switch arm, an operating-lever, as B, connections from theoperating-lever to the reversingswitch lever and to the main-switch armwhereby the reversing-switch may be closed before the main switch, thearrangement being such that the main switch will be closed regardless ofthe direction of movement of the reversing-switch lever, arheostat-lever, a cam controlling it and an actuating-lever, the motionof the operating-lever B being transmitted to the main-switch leverthrough the actuating-lever and the actuating-lever having amovementindependent of both the main-switch lever and the cam wherebythe switch and rheostat are caused to operate in succession.

In testimony whereof I subscribe my signature in presence of twowitnesses.

ROBERT IVILSON.

Witnesses:

W. E. HEDGCOCK, A. E. Soorr.

